Catalysts for the addition polymerization of unsaturated organic compounds



Patented July 3.1, 1945 UNITED STATES PATENT OFFICE CATALYSTS FOR THEADDITION manua- IZATION COMPOUNDS wmlamustenn, B.F.Goodrlchoorporationolliew 0F UNSA'I'UBATED OIGANIO Akron, Company, New York, N.12, a

York

No Drawing. Application February 19, 1041,

' Serial No. 819,117

18 Claims. (Cl. 260-84.!)

composed of naturally occurring compounds 01' thecyclopentenophenanthrene group having a heavymetal salt combinedtherewith. Among the naturally occurring compounds or thecycloparticularly to the polymerization of coniugated openienophenanthrene group which, when combutadienes either alone, inmixtures with one bined with a heavy metal salt as hereinafter deanotheror with other polymerizable comonomers scribed, are eflective aspolymerization accelerasuch as the vinyl and vinylidene compounds. torsthere may be mentioned the sterols such as The principal object of theinvention is to provide cholesterol, coprosierol, zymosterol,stlgmasterol, a new class of catalysts or accelerators oi polyl0ergosterol, sitosterol, ostreasterol, lanosterol, agmerization by theuse oi which improved polynosterol. scymnol and the like; the bile acidsinmers may be obtained in increased yield and in a eludingthoseoocurring in or bile such as lithomuch shorter interval oi'time. 4cholic acid, desoxycholic acid. cholic acid, and the It is known thataddition polymerizations may like, those occurring in human bile such asanbe initiated and promoted by the presence oi var- 1sthropodesoxycholic acid and other bile acids ociolls substances amongwhich are oxygen and curring in the bile of other animals such as oxygenyielding compounds such as hydrogen ursodesoxycholic acid (bear bile),bui'odesoxyperoxide, organic peroxides and per-salts. Howcholic acid(toad bile). hyodesoxycholic acid (pig ever, with the use of such knowninitiators conbile) and nutriacholic acid (beaver bile): the siderablediiflculty is still experienced in obtain- 20 sapogenins oi the cholanesaponins such as tigoing high yields of a desirable polymer in a shortnin it genin, digitogenin, sarsapogenin and interval of time.Particularly in the commercial th like; the aglycones of the vegetablecardiac manufacture of Polymers by emulsion polymerim; such adigitaligenin, it ng m and th zation, the production schedule isfrequently disik th m poisons uch as burnt-aim; and th P by "5640115 and10x18 induction 26 sex hormones such as androsterone, testosterone,periodsbeiore the polymerization starts. ash-one and pmgmmng Thecompounds I have now discovered a large number oi subare all relatedchemically since they contain t stances which have been termed redoxsystems cyclopentenophenmmrenemmcture because oi their property 01'catalyzing or promoting o ation reduction reactions, particuo larly thosf urring in biological processes, which substances are quite eilectivein promoting addition polymerisations and which are vastly superior toany previously described polymerization initiators or accelerators inthat the poLY- 35 merization is carried out in a much shorter time, theinduction period is largely eliminated, lower Y temperatures for thepolymerization may be emand all have substituents present at both the C:ployed and consequently a higher molecular position and the C11position, the substituent at weight more linear polymer possessing morede- 40 the C: position containing an oxygen atom. The sirable propertiesis obtained. chemical relationship oi tlmse compounds may be The classof redox systems with which the presshown by the following table whichsets forth 'ent invention is concerned is that classwhich is theirchemical structure in a general way:

Type oi compound jgfg m Bubstitusnt at 0n position am- Starch OHSaturated cal-unsaturated aliphatic hydro- Double bond between 0; and C;CH.

ar lg n side chain containing 3-1] mrbon groups at Q and 01s. g sasmnmeis's s-isms. m

Bapogeninsoieholans saponins.-. 0H Eight carbon atom side chaincontaining Other-0B grouplatothpodtiona.

M I cardiac -on sfi'nr'fi'sfi h' a'as m mm on: a pa priniapally a 0.. 0"5 mum! otherzlmorygen atom and a kstonio 017- and Cu polka. roam 0Hsals- [or aglyoones a vegetable cardiac Other-Ofluourlatothnpoaitionl.

8s: hormones =0 5 ail. --CCB: or luiilar group.--.. Double bond batwalnO and 0 -As hereinabove-stated these naturally occurgroups are electivein promoting polymerizations when combined with a heavy metal compound.The term "heavy metal" as used herein is meant to include metallicelements which have a density greater than four, an atomic weightgreater than forty and a low atomic volume (ratio of atomic weight todensity) and consequently appear substantially at the minimum pointsabove an atomic weight of forty on Lothar Meyer's curve 01' atomicvolumes. (See any standard textbook of inorganic chemistry such asEphraim, Textbook of Inorganic Chemistry," page 30, or Caven and Lander,"Systematic Inorganic Chemistry," tacing page 30.) The term "heavy metalincludes, therefore, those metallic elements appearing in the centerpositions of the long periods of a periodic table arranged in short andlong periods, and especially those occurring in the 6th to 12thpositions 01' the long periods (considering ,the alkali metals to occupythe first position and all the rare earth metals to occupy a singleposition), that'is, the elements occurring in group VIII of theMendeleef Periodic Table such as iron, cobalt and nickel, those insubgroup B of groups I and II of the Mendeleef Periodic Table such ascopper, silver, zinc, cadmium and mercu y, and those in subgroup Agroups VI and VII of the Mendeleei' Periodic Table such as chromium,manganese and molybdenum.

The class of redox systems of this invention is meant to include broadlythose systems which contain any of the heavy, metals mentioned above inthe form of one 01' its salts combined witli a y .of thecyclopentenophenanthrene type comring compounds 01' thecyclopentenophenanthrene in a non-solvent liquid, usually water, withthe aid of an emulsiiying agent and polymerimtion is then attested byadding the system containing a heavy metal and a sterol or relatedcompound together, if desired, with various other substances. the nature01 which will be described hereinafter, and agitating the emulsion untilpolymer is formed. The resulting polymerized emulsion containing polymerparticles dispersed in a liquid medium greatly resembles natural rubberlatex and may be coagulated in the usual manner to yield the solidpolymer. The amount of the redox systems to be use in polymerization maybe varied over rather wide limits provided that an excessive amount ofthe heavy metal salt is preferred. -When using some heavy metals,particularly copper and manganese, however, it is desirable to use evensmaller concentrations of the heavy metal salt, less than .1%, sincethese metals in higher concentration tend to inhibit the polymerization.

As has been mentioned hereinabove, the redcx systems oi! this inventionmay be used, generally, in the polymerization of these unsaturatedorganic compounds which are capable of undergoing an additionpolymerization to form a high molecular weight linear polymer. Includedin this class of monomers are the conjugated butadienes such asbutadiene, isoprene, dimethyl butadiene, chloroprene, piperylene and thelike all or which contain ,a v

butadienes such as a mixture of butadiene and pentenophenanthrene typecompound itself or some naturally occurring substance winch contains thecompound or one 01 its derivatives. For example, a mixture oi a heavymetal salt such as cobalt chloride and cholesterol or a lipid whichyields cholesterol on hydrolysis may be employed, or cobalt chloride maybe used together with an animal bile known to contain bile acids or withglucosides from certain plants which are known to contain eithersaponins or the cholane "group which yield sapogenins on hydrolysis or.cardiac poisons which yield their aglycones on hydrolysis. Watersoluble redox systems containing a sterol or a bile acid combined with awater soluble salt of a commonly occurring heavy merized by' well knownmethods oi' polymerization such as y polymerization in homogeneoussystemsor by polymerization in emulsions in presence or catalyticamounts ofthe redox systems 01' this invention. In the emulsionpolymerization process which is at presentpreierred, the monomer ormonomer mixture is emulsified dimethyl butadiene; and monomer mixturesof one or more of these conjugated butadienes with one or more othercompounds which also conacrylate. butyl acrylate, methacrylamide and thelike and other vinyl' compounds such as vinyl ketones, vvinyl ethers,vinyl carba'zole, vinyl i'urane and the like. Monomer mixtures oibutadienes with othercompounds containing a s group such as vinylidenechloride and the like may' also be used. All these monomers and monomermixtures when polymerized or copclymerized in the manner hereindescribed torm high molecular weight linear polymers. When theconlu'gated butadiene is the monomer or is the predominant constituentof a monomer mixture such polymers are rubbery in character and may becalled synthetic rubber.

Other monomers or monomer mixtures which are capable of undergoing anaddition polymerization and which may be used in the process of thisinvention are the above-mentioned vinyl and vinylidene compounds as wellas other vinyl conipounds such as vinyl chloride and vinyl acetate,either alone or in mixtures with one another, all of which polymerize toyield a linear polym r of a thermoplastic resinous character.

The redox systems of this invention containing a heavy metal and asterol or related compound may be used in the polymerization of monomersin emulsions prepared with various emulsifying agents and containingvarious other catalysts,

initiators, promoters, accelerators or modifiers of polymerization. Asemulsifying agents, partially neutralized fatty acid soaps such as70-90% neutralized myristie or palmitic acid are particularly effectivebut other well known emulsifying agents including completely neutralizedfatty acid soaps such as sodium oleate and sodium palmitate and hymolalsulfates or sulfonates such as sodium lauryl sulfate and sodium isobutylnaphthalene sulfonate may also be employed.

The redox systems containing a sterol or related compound and a heavymetal salt are preferably used to accelerate polymerization initiatedwith an oxygen yielding compound such as hydrogen peroxide, benzoylperoxide, potassium persulfate, sodium perborate, potassium percarbonateand the like, but may also be employed with other known polymerizationinitiators such as diazoaminobenzene, trichloracetic acid and carbontetrachloride. The redox systems of this invention may also be usedadvantageously in polymerizations which employ a reducing agent such assulfur dioxide as the polymerization initiator, or in polymerizationseffected in presence of both an oxidizing and a reducing agent. Moreoverthe redox systems disclosed herein may be used to effect polymerizationscarried out in the absence of an added initiator, such polymerizationsbeing incapable of proceeding without the redox system. They may also beemployed in the polymerization of emulsions containing a polymerizationmodifier such as the dialkyl dixanthogens, diaryl disulfides, thiuramdisulfides and other sulfur containing compounds known to increase thesolubility and plasticity of polymers.

Although the exact manner in which the redox systems containing a sterolor related compound and a heavy metal accelerate polymerization is notknown with certainty, it is believed that the redox system promotes orcatalyzes an oxidation reduction reaction which oxidizes or activatesthe monomer molecules to such an extent that they are then capable ofinitiating a chain reaction which produces a linear polymer. The redoxsystem may directly catalyze the oxidation of the monomer by anoxidizing agent such as a peroxide, if such is present, or it may beauto-oxidizable, and be capable of inducing monomer oxidation oractivation by an oxidation reduction involving the redox system itself,or some other mechanism may be responsible for the increase in the rateof polymerization and for the improved properties of the polymerizationproducts. The association of small amounts of heavy metals with variousphysiologically active compounds such as those of thecyclopentenophenanthrene type in biological systems which undergooxidoreduction is well known and many theories have been propounded foran explanation of such biological oxidoreductions. Since it is believedthat the initiation of polymerization reactions is quite similar tobiological oxidation reductions particularly as regards the role of theredox catalyst, analogies of polymerization systems with biologicalsystems have proved of great value in elucidating the action of theredox systems of this invention. It is to be understood however, thatthe invention is not to be limited by any proposed theory since theinclusion of the substances herein described and herein designated asredox systems in polymerization mixtures greatly accelerates the processand also improves the quality of the polymerization products.

In order to illustrate the practice of this invention and to show theaccelerating effect of the redox systems of this invention uponpolymerization, an emulsion containing the following ingredients isprepared. Butadiene g Acrylonitrile "g-.. 45 Hydrogen peroxide (ilsolution) cc 10 Emuisifylng solution (2% aqueous solution of myristicacid neutralized with NaOH) cc 250 Polymerization modifier g. 0.3

This emulsion is then divided into equal parts and redox systems addedto the emulsion as follows:

(1) No redox system added-control (2) 0.05% by weight of ferrousammonium sulfatecontrol 0.05% byweight (based on monomers) of ferrousammonium sulfate 0.50% by weight (based on monomers) of cholesterol0.05% by weight of ferrous ammonium sulfate 0.50% by weight of ox bile0.05% by weight of cobalt chloride 0.50% by weight of ox bile 0.001 byweight of cuprous chloride 0.50% by weight of cholesterol ('7) 0.10% byweight of cuprous chloride The emulsions are then placed in sealed glasstubes and rotated at 30 C. At various intervals the percent yield ofpolymer is determined. The rate of polymerization for the various tubesis shown as follows:

Per cent Per cent Per cent Percent Per cent Tube yield after yield afteryield after yield after yield after 7 hours 10% hours 12 hours 23 hours45 hours 26 31 ill A It may be seen that with no redox system added, thepolymerization is not started after 12 hours and is not complete until45 hours; with an iron salt alone, 23 hours are required; while with theredox systems of this invention containing a heavy metal salt and asterol or a bile acid, polymerization is substantially complete afteronly 12 hours. With a copper salt alone, there is no polymerization evenafter 45 hours, but with a copper salt and cholesterol polymerizationwas substantially complete in 12 /2 hours.

Other embodiments of the invention in which various other compounds ofthe cyciopentenophenanthrene type are used with various heavy metals andwith various monomer mixtures, initiators, and emulsifying agents alsoshow that the polymerization velocity is increased by the practice ofthis invention, It is even possible to polymerize a butadiene vinyl typecomon'omer mixture in an aqueous emulsion containing only a heavy metalsalt and a sterol or bile acid without any initiator other thanmolecular oxygen being present and in the absence of any addedemulsifying agents. This is possible because the sterols and bile acidsin addition to their accelerating effect also act as emulsiiying orsolubilizing agents to emulsii'y the monomers in the aqueous phase. 1 Itis sometimes advantageous therefore to employ sterols or animal bile inpolymerization mixtures containing other redox systems which contain aheavy metal salt combined with other compounds including sodiumpyrophosphate, levulinic acid, beta mercapto ethanol and quebrachitolsuch as are disclosed in copending applications of William D. Stewart,Serial Nos. 379,713 to 379,716, inclusive, filed Feb. 19 1941, since thepresence of these substances aid in the formation of an emulsion whichmore closely resembles the emulsions present in biological systems.However, it is understood that the use of bile or bile salts asemulsifying agents is known to the art and hence no claim is made onthis feature of the invention.

Although various embodiments of the invention have been hereindisclosed, it is not intended that the invention be limited solelythereto for it will be obvious to those skilled in the art that manymodifications and variations are within the spirit and scope of theinvention as defined by the appended claims.

I claim:

1. The method which comprises subjecting a polymerizable materialconsisting of at least one unsaturated organic compound which contains aular weight linear polymer, to polymerization in aqueous emulsion in thepresence of a catalyst CHFC comprising a water soluble heavy metal saltin combination with a naturally occurring compound containing acyclopentenophenanthrene ring having a substituent containing noelements other than oxygen and hydrogen at the Ca position, a

substituent containing no elements other than carbon, hydrogen andoxygen at the Cu position and no substituents containing elements otherthan carbon, hydrogen and oxygen at other positions, the totalconcentration of the heavy metal salt and the combinedcyclopentenophenanthrene compound being less than 2% by weight of thematerial polymerized, and the concentration of the heavy metal saltbeing such that the polyme'r'i'zation proceeds more rapidly than in theabsence of the heavy metal salt.

2. The method of claim 1 in which the material subjected topolymerization is,a polymerizable conjugated butadiene.

3. The method of claim 1 in which the material subjected topolymerization is a mixture of a polymerizable conjugated butadiene andat least one other compound which contains a CHFC/ group and iscopolymerizable therewith in aqueous emulsion.

4. The method of claim 1 in which the material subjected topolymerization is a mixture of butadiene-1,3 and at least onecopolymerizable vinyl compound.

5. The method which comprises subjecting a mixture of a polymerizableconjugated butadiene and at least one other compound which containsgroup and is copolymerizable therewith in aqueous emulsion, topolymerization in aqueous emulsion in the presence of a catalystcomprising a sterol combined with a water-soluble heavy metal salt, thetotal concentration of the sterol and the heavy metal salt being lessthan 2% by weight of the material polymerized and the concentration ofthe heavy metal salt being such that the polymerization proceeds morerapidly than in the absence of the heavy metal salt.

6. The method of claim 5 in which the heavy metal salt is a salt of aheavy metal occurring in the 6th and 12th positions of the first longperiod of the periodic table. a

'7. The method of claim 5 in which the heavy metal salt is a salt 01' aheavy metal occurring in group VIII and the first long period of theperiodic table.

8. The method which comprises subjecting a mixture of butadiene-1,3 andat least one copolymerizable vinyl compound to polymerization in aqueousemulsion in the presence of a catalyst comprising cholesterol combinedwith a watersoluble salt of a heavy metal occurring in the 6th to 12thpositions of the first long period of the periodic table, the totalconcentration of cholesterol and the heavy metal salt being less than 2%by weight of the material polymerized and the concentration of the heavymetal salt being such that the polymerization proceeds 'more rapidlythan in the absence of the heavy metal salt.

9. The method of claim 8 in which the heavy metal salt is a salt of aheavy metal occurring in group VIII and the first long period of theperiodic 10. The method of claim 8 in which the heavy metal salt is aniron salt. a

11. The method of claim 8 in which the material polymerized is a mixtureof butadiene-1,3 and acrylonitrile and the heavy metal salt is an ironsalt.

12. The method which comprises subjecting a mixture of a polymerizableconjugated butadiene and at least one other compound which contains agroup and is copolymerizable therewith in aque- CH C ous emulsion, topolymerization in aqueous emul- I polymerization proceeds more rapidlythan in the absence of the heavy metal salt.

13. The method of claim 12 in which the material polymerized is amixture or butadiene-1,3 and at least one copolymerizable vinylcompound, and the heavy metal salt is a salt of a heavy metal occurringin the 6th to 12th positions of the first long period. of the periodictable.

14. The method of claim 12 in which the catalyst comprises ox bile anda, water-soluble salt of a heavy metal occurring in the 6th to 12thpositions of the first long period of the periodic table.

15. The method of claim 12 in which the material polymerized is amixture of butadiene-1,3

and acrylonitrile and the catalyst comprises ox bile and a water-solublecobalt salt.

16. The method of claim 12 in which the material polymerized is amixture of butadiene-1,3 and acrylonitrile and the catalyst comprises oxbile and a water-soluble copper salt.

17. The method which comprises subjecting a mixture of a polymerizableconjugated butadiene and at least one other compound which contains aClix-=0 group and is copolymerlzable therewith in aqueous emulsion, topolymerization in aqueous emulsion in the presence of a catalystcomprising a complex compound of a heavy metal and a compound containinga cyclopentenophenanthrene ring having a substltuent containing noelements other than oxygen and hydrogen at the C: position, asubstituent containing no elements other than carbon, hydrogen andoxygen at the C11 position and no substituents containing elements otherthan carbon. hydrogen and oxygen at other positions, the concentrationof the complex compound being less than 2% by weight of the materialpolymerized and such that the polymerization proceeds more rapidly thanin the absence of the complex com- 7 pound.

18. The method of claim 17 wherein the heavy metal is a heavy metaloccurring in the 6th to 12th positions of the first long period of theperiodic table.

- WIILIAM D. S'I'EWART.

Certificate of Correction Patent No. 2,380,477.

WILLIAM D. STEWART July 31, 1945.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring claim 6, for 6th and 12th be readwith this correction therein that th case in the Patent Oflice.

correction as follows: Page 4, second column, line 26, read 6th to 12th;and that the said Letters Patent should e same may conform to the recordof the Signed and sealed this 5th day of November, A. D. 1946.

LESLIE First Assistant Oommz'uioner of Patents.

occurring in the 6th to 12th positions of the first long period. of theperiodic table.

14. The method of claim 12 in which the catalyst comprises ox bile anda, water-soluble salt of a heavy metal occurring in the 6th to 12thpositions of the first long period of the periodic table.

15. The method of claim 12 in which the material polymerized is amixture of butadiene-1,3

and acrylonitrile and the catalyst comprises ox bile and a water-solublecobalt salt.

16. The method of claim 12 in which the material polymerized is amixture of butadiene-1,3 and acrylonitrile and the catalyst comprises oxbile and a water-soluble copper salt.

17. The method which comprises subjecting a mixture of a polymerizableconjugated butadiene and at least one other compound which contains aClix-=0 group and is copolymerlzable therewith in aqueous emulsion, topolymerization in aqueous emulsion in the presence of a catalystcomprising a complex compound of a heavy metal and a compound containinga cyclopentenophenanthrene ring having a substltuent containing noelements other than oxygen and hydrogen at the C: position, asubstituent containing no elements other than carbon, hydrogen andoxygen at the C11 position and no substituents containing elements otherthan carbon. hydrogen and oxygen at other positions, the concentrationof the complex compound being less than 2% by weight of the materialpolymerized and such that the polymerization proceeds more rapidly thanin the absence of the complex com- 7 pound.

18. The method of claim 17 wherein the heavy metal is a heavy metaloccurring in the 6th to 12th positions of the first long period of theperiodic table.

- WIILIAM D. S'I'EWART.

Certificate of Correction Patent No. 2,380,477.

WILLIAM D. STEWART July 31, 1945.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring claim 6, for 6th and 12th be readwith this correction therein that th case in the Patent Oflice.

correction as follows: Page 4, second column, line 26, read 6th to 12th;and that the said Letters Patent should e same may conform to the recordof the Signed and sealed this 5th day of November, A. D. 1946.

LESLIE First Assistant Oommz'uioner of Patents.

